(OPRAH.com) -- Personally, I like my pizza deliveryman to do one thing: bring me my dinner. But mention this guy to a group of women, and, while most of us will think of cheesy pies with tomato sauce, a good number of us will conjure up that hilariously bad porn cliché, the randy fellow who's always ready to accept sex in exchange for a medium sausage and mushroom.

Some pornographers are marketing to women.

Notwithstanding how lame the cliché is, or how simply bad most porn is (and after ten years as a professional reviewer of the stuff, I can report that much of it is very bad), the fact is, millions of women use and enjoy "explicit sexual imagery."

What's perhaps more surprising, given the latest scientific research, is that more of us don't.

In the first three months of 2007, according to Nielsen/NetRatings, approximately one in three visitors to adult entertainment Web sites was female; during the same period, nearly 13 million American women were checking out porn online at least once each month.

Theresa Flynt, vice president of marketing for Hustler video, says that women account for 56 percent of business at her company's video stores. "And the female audience is increasing," she adds. "Women are buying more porn." (They're creating more of it, too: Female director Candida Royalle's hard-core erotic videos, made expressly for women viewers, sell at the rate of approximately 10,000 copies a month.) Watch man fired over porn-star wife »

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Meanwhile, science is finally buying into the idea that women are at least as stimulated by porn as men.

In a 2006 study at McGill University, researchers monitored genital temperature changes to measure sexual arousal and found that, when shown porn clips, men and women alike began displaying arousal within 30 seconds; men reached maximum arousal in about 11 minutes, women in about 12 (a statistically negligible difference, according to the study).

Even more compelling were the results of a 2004 study at Northwestern University that also assessed the effect of porn on genital arousal. Mind you, a copy of "Buffy the Vampire Layer" and a lubed-up feedback device isn't most girls' idea of a hot night in. But when the researchers showed gay, lesbian, and straight porn to heterosexual and homosexual women and men, they found that while the men responded more intensely to porn that mirrored their particular gender orientation, the women tended to like it all. Or at least their bodies did. Oprah.com How to feel good naked

But that's the hitch: Even when our bodies respond to what we're seeing, not every woman feels empowered to enjoy the show. For years we've been told that we won't -- or shouldn't -- be turned on by porn, end of story, sleep tight.

The message has come from all sides -- from conservative Christian organizations ("Traditionally, women are far more likely to engage in wistful, romantic fantasies than crude scenes of people engaging in sexual acts," Kathy Gallagher, cofounder of Pure Life Ministries, has written) to the radical feminist Catharine MacKinnon (who says porn exploits and discriminates against women, and encourages rape).

When everyone tells you that what you might be curious about, or even secretly like, is wrong, bad, sleazy, and shameful, you don't have to cast a line very far to land a set of inhibitions.

And, indeed, many a smart, strong, sexually self-reliant girl has popped in a porn DVD and ejected it just as quickly because she saw something that offended her or made her uncomfortable.

I've heard from many women that they don't like the sense of being "out of control" they get from watching porn -- that disconnect between how their body is feeling and what their brain is telling them is acceptable. I like to remind these women that porn won't make you do anything you didn't already want to do before you pressed Play on the "Edward Penishands" DVD. Oprah.com: What you still don't know about sex

I've also heard, plenty of times, that porn degrades women. That argument always makes me wonder about gay male porn, which lots of women appreciate for all its hunky hotties in flagrante. If heterosexual porn degrades women, does gay porn degrade men? What about porn made by women -- is that degrading, too?

For me, the real problem with most porn is its hokeyness -- the ridiculous costumes, the awful cinematography, the ludicrous story lines, the terrible acting (not to mention how scary the close-ups sometimes look, how fake the boobs are, how some starlets really sound like injured animals...).

And yet in my research and experience, the biggest roadblock for women (and men) to enjoying explicit imagery is the fear that they don't "stack up" to the bodies and abilities of the people onscreen. Erotic models and actresses bring up a whole range of adequacy issues, from breast size to weight, from what you look like "down there" to the adult acne we all periodically fight.

But it's worth remembering that if porn performers looked like you and me, they'd be out of a job. They're abnormally thin, they get cosmetic surgery literally (and sometimes frightfully) from head to toe, they have makeup in places you'd be surprised makeup can be applied, they shave and wax everything imaginable, and they're weirdly flexible. They occupy a tiny end of the gene pool, and that's why they're capable of acting out fantasy sex. Oprah.com: 5 secrets of the female orgasm

Though I've sometimes felt that my job as a porn reviewer (for Web sites like FleshBot.com) is akin to being a canary in a bad-taste boys' club mine shaft, I've seen a change in quality in the past few years that I think is a direct reflection of the growing female audience. As more discriminating viewers, we've demanded better porn -- and lo, it is being made.

So just what do we love about it? First, the way it lets us satisfy our very normal, very human sexual curiosity. If you're like me, you're the kind of woman who'll peep at Pam Anderson's new boob job just to see the latest installations. But it's not just what the bodies look like, it's what they look like aroused -- and what they can do. Watching people have sex can be fascinating.

Porn is also a fun and versatile toy. Sure, I sometimes feel like I need Google Earth to show me where the good porn is, but once I find it, I can figure out what to do with it faster than you can click Zoom In.

Explicit sexual imagery is an aphrodisiac; it sends a direct current buzzing from our brains to our groins. Like a reliable vibrator, it can be a great tool. With porn, women like me get to experiment with making adult choices and trying on new fantasy ideas, just as we might try a different brand of condom for a change.

We don't have to think of rationality and animalistic urges as mutually exclusive. If we desire, we can let them play together like tennis doubles. Porn is one more pleasure to add to life's sexual buffet, one that can be enjoyed with a partner or alone. And if "Shaving Ryan's Privates" winds up giving you more giggles than orgasms, then the only casualty is...Ryan's privates.